Efforts are being made to reduce the size and packaging of atomic sensors, including atomic clocks. One way to accomplish this is to reduce the size of the physics package for the atomic sensor. One example of a physics package is a glass block that is machined and sealed to maintain an ultra-high vacuum. The glass block includes a plurality of faces on its exterior and a plurality of angled borings that serve as light paths for the physics package. Mirrors and windows are fixedly attached over the exterior openings of the light path bores to seal the physics package. A cavity evacuation structure is attached to provide means for initial vacuum evacuation of the physics package. A sample container is attached to hold the atomic sample used as the frequency reference for the atomic sensor. Atomic sensors which operate by trapping and cooling atoms from a background vapor into a magneto optical trap (MOT) or optical molasses can be sensitive to the size of the optical beams. For example, the signal to noise ratio in such systems scales as the square of the beam size.